NanoShell Wiki
Overview of Nanoshells A nanoshell is nanoparticle that contain a very small dielectric core which is surrounded by a thin sheet of metal. By changing the radius and thickness of the core and metal shell, the nanoshells are able to absorb different electromagnetic wavelengths. Nanoshells can absorb light of various wavelengths including infrared. When nanoshells are exposed to their corresponding wavelength they begin to oscillate which either causes light to be absorbed or scattered (Wang et al., 2004). Current Status of Research One area of research includes the treatment of cancer and tumors. By increasing the radius of the core and decreasing the thickness of the shell, the nanoshell are able to absorb infrared. These nanoshell can be deployed to areas of tumor development where near infrared light can be applied, thus heating the particle and killing nearby tumorous cells. Gold nanoshells have been the primary candidate as they strongly absorb Near Infrared Light(800nm), with infrared light being able to penetrate tissue, and covert it to heat (Wang et al, 2004) . Trials using mice models have been successful in removing tumors using nanoshell-assisted photo-thermal therapy (Photo-thermal tumor ablation in mice using near infrared-absorbing nanoparticles, 2004). In a recent experiment conducted by East China Normal University and Tongji University, they were able to develop "smart" gold nanoshells which were coated with an anticancer drug, doxorubicin and peptide A54 that were able to effectively kill cancerous liver cells while not damaging surrounding healthy cells. The uptake of the Gold nanoshells to cancer liver cells with the peptide A54 was three times more effective than without the peptide A54 (Liang, Z., Li, X., & Liu, S, 2014). Clinical trials are currently being conducted. Availability of Nanoshells Various sizes of nanoshells can be purchased commercially. Nanoshells can be purchased from a variety of website that offer worldwide shipping including nanocomposix.com. No professional training or certification is required. They can be purchased for a few hundred dollars per 100ml. Current and/or future applications of Nanoshells Nanoshells are still being researched and are only used in lab settings. However there are promising future applications of nanoshells in the bio-medical industry. Since nanoshells have a large optical absorption spectrum and scattering cross-section they can be used for imaging, tissue welding/bonding, drug delivery, and treatment of cancer (De Jong, W. H., & Borm, P. J, 2008). In cancer treatment, nanoshells can naturally buildup in tumors sites as tumors have many defective blood vessels that nanoshells are able to slip through and accumulate in. An infrared light can then be applied to heat the nanoshellls killing the tumor (Working With Nanoshells, 2005). Nanoshells can also be used as a contrasting agent to allow for high resolution imaging in vascular systems due to their scattering cross-section. This can potentially aid in the treatment and monitoring of vascular diseases and tumor treatment. Since gold is known for its biocompatibility, proteins, antibodies, and drugs can be attached to it and be used in treatment of other diseases. In addition, due to their large optical absorption spectrum, tissue welding with nanoshells is possible (Hirsch et al,2004). Health and safety precautions Environmental impact Gold nanoshells do not directly impact the environment; They are non-toxic and do not present a hazard. However the materials that consist of the nanoshells are found through mining and thus indirectly impact the environment. Impacts of mining include erosion, loss of biodiversity, contamination of soil and water. Risk-benefit analysis Benefits * non-invasive treatment of cancer * high resolution imaging for cancer and tumor detection * bio-compatible; not toxic to cells (De Jong, W. H., & Borm, P. J, 2008) * gold surface allows attachment of certain proteins/drugs for drug delivery (De Jong, W. H., & Borm, P. J, 2008) * production is done with safe chemicals; usually in aqueous-based solutions and results in little waste. Safe process and produces no dangerous fumes (Working With Nanoshells, 2005). * Better alternative to chemotherapy * no direct environmental impacts * specially developed nanoshells are biodegradable (Troutman et al, 2008) Risks * Gold allergies * No long term health effects have been studied Customer acceptance Gold nanoshells can provide doctors and professions better tools for the assessment and treatments of patients. Additionally, nanoshells offer a better alternative to current treatments of cancer, they do not harm the environment and do not pose any major health risks. As a result, the acceptance of nanoshells is promising. Regulations or guidelines already in place and suggestions for future regulation Clinical studies are restricted to FDA sanctioned sites. According to Health Canada, "For nanomedicines, Health Canada applies the Food and Drug Regulations and the Medical Devices Regulations under the authority of the Food and Drugs Act, so that medical devices and pharmaceutical drugs are safe, effective and of high quality(Frequently Asked Questions Related to the Policy Statement on Health Canada's Working Definition for Nanomaterial, 2011)." Currently, engineered nanoparticles have no special regulations for production, handling, or labeling. Since nanoshells do not pose any health risks nor any direct environment risks, there should be lenient regulations to allow the development and use of this technology. Production should be regulated for minimal environmental impact and quality of nanoshells in the use of medicines. APA References Agnico-Eagle Photograph. (2007). Retrieved March 4, 2015, from:http://commons.wikimedia.org/wiki/File:Kittilla,_Finland;_Open_Pit_Mine.jpg Cancer Treatment - AuroLase Therapy, Cancer, Tumors, Nanoshells, Nanoparticles, Nanotechnology, Nanomedicine. (n.d.). Retrieved February 28, 2015, from http://www.nanospectra.com/technology/aurolasetherapy.html De Jong, W. H., & Borm, P. J. (2008). Drug delivery and nanoparticles: Applications and hazards. International Journal of Nanomedicine, 3''(2), 133–149. Frequently Asked Questions Related to the Policy Statement on Health Canada's Working Definition for Nanomaterial. (2011, May 20). Retrieved March 3, 2015, from http://www.hc-sc.gc.ca/sr-sr/pubs/nano/faq-eng.php Gobin, A. M., O'Neal, D. P., Watkins, D. M., Halas, N. J., Drezek, R. A. and West, J. L. (2005), Near infrared laser-tissue welding using nanoshells as an exogenous absorber. Lasers Surg. Med., 37: 123–129. doi: 10.1002/lsm.20206 Gold Nanoshells. (n.d.). Retrieved February 28, 2015, from http://nanocomposix.com/collections/nanoshells Hirsch, L. R., Stafford, R. J., Bankson, J. A., Sershen, S. R., Rivera, B., Price, R. E., … West, J. L. (2003). Nanoshell-mediated near-infrared thermal therapy of tumors under magnetic resonance guidance. ''Proceedings of the National Academy of Sciences of the United States of America, 100(23), 13549–13554. doi:10.1073/pnas.2232479100. Retrieved February 27,2015, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC263851/ Liang, Z., Li, X., & Liu, S. (2014). ‘Smart’ gold nanoshells for combined cancer chemotherapy and hyperthermia.Biomedical Materials, 9''(2). Retrieved February 27, 2015, from http://iopscience.iop.org/1748-605X/9/2/025012 Photo-thermal tumor ablation in mice using near infrared-absorbing nanoparticles. D. Patrick O'Neal, Leon R. Hirsch, Naomi J. Halas, J. Donald Payne, Jennifer L. West Cancer Lett. 2004 June 25; 209(2): 171–176. doi: 10.1016/j.canlet.2004.02.004 Robert Dibrell Eric Berger (n.d). Fighting Tumors with Gold Nanoshells infographic, Retrieved March 4, 2015, from:http://blog.chron.com/sciguy/2008/07/at-long-last-nanoshells-enter-clinical-trials/ Troutman, T. S., Barton, J. K., & Romanowski, M. (2008). Biodegradable Plasmon Resonant Nanoshells. ''Advanced Materials (Deerfield Beach, Fla.),20(13), 2604–2608. doi:10.1002/adma.200703026 Wang, Y., Xie, X., Wang, X., Ku, G., Gill, K., O'neal, D., ... Wang, L. (2004). Photoacoustic Tomography of a Nanoshell Contrast Agent in the in Vivo Rat Brain. Nano Letters, 1689-1692. Working With Nanoshells. (2005, January 5). Retrieved March 3, 2015, from http://www.pbs.org/wgbh/nova/body/halas-nanoshell.html figure of noninvasive PAT of a rat brain in vivo with and without nanoshells . Retrieved March 4, 2015, from: http://oilab.seas.wustl.edu/epub/2004YW-NL.pdf graph of gold nanoshells absorption with various shell thickness . Retrieved March 4, 2015, from: http://nanotechnologie-contre-cancer.e-monsite.com/medias/images/au-wavelength-1.jpg photograph of 80 nm Silica with gold nanoshells . Retrieved March 4, 2015, from: http://nanocomposix.com/collections/nanoshells Category:Browse